Vinification vats exist which are capable of being rotated and which include peripheral helical slopes or ramps intended firstly to break up and immerse the marc which forms during vinification, and secondly to extract the marc when vinification is over. Such vats include a door located:
near the periphery of the end of the vat (the Egretier type); or
near the middle of the end off the vat (the CMMC type).
In both cases the helical slopes extend up to the racking orifice, but in the first case implementation is simple since the end of the vat bulges outwardly, while in the second case the end of the vat is frustoconical which makes it difficult to implement and also makes implementation of the helical ramp difficult.
Further, in the first case and as a function of the diameter of the vat, the marc is collected in a hopper of greater or lesser size since evacuation takes place during rotation over a fraction of a turn of the cylinder occupying a few tens of degrees.
However, in the second case, it takes a long time to empty the vat and this can lead to the marc becoming oxidized.
The main aim of the invention is to mitigate these various drawbacks by providing a fast extraction device (no oxidation), suitable for all kinds of vats (thereby saving money with flat or bulging ends), and using marc-collecting hoppers of small size (racking orifice near the axis of the vat).